A Fossil Feather from the Oligocene of Central Mexico

From the sedimentary sequence of the Los Ahuehuetes Locality (Oligocene) near Tepexi de Rodriguez, Puebla, Mexico, a fossil contour feather was collected. It is well preserved as a carbonaceous compression, oval in outline, and measures 33.6 mm in length by 17 mm in width. The fossil feather seems to represent a dorsal surface. Barbs are filamentous, cohesive, and form nearly symmetrical outer and inner vanes. Although microstructure is not well preserved, a distinction between proximal barbules and the shorter distal barbules is possible. In Mexico, this fossil represents the first report of a fossil feather from the country and it is among the oldest record of the Class Aves only younger than the skeletal elements of an enanthiornithine bird and some neognathus eggshells from the Late Cretaceous of the State of Baja California.